Surfactant

Abstract

A surfactant for water/supercritical carbon dioxide microemulsions that can achieve high water dispersion ability, water/supercritical carbon dioxide microemulsion forming ability under a moderate condition, and high water solubilization rate and that reduces burden on the environment and ecosystem. Provided are a surfactant for stabilizing a water/supercritical carbon dioxide microemulsion including a compound of Formula (I) and a water/supercritical carbon dioxide microemulsion including the surfactant. The compound of Formula (I) has the structure:

The invention claimed is: 
     
       1. A water/supercritical carbon dioxide microemulsion comprising a surfactant, wherein the surfactant has a concentration of 10 −10 % by mol to 10 2 % by mol based on a molar amount of the supercritical carbon dioxide and the surfactant comprises a compound of Formula(1): 
       
         
           
           
               
               
           
         
       
       where Rf is a C 1-7  perfluoroalkyl group, M is a hydrogen atom, an alkali metal, ammonium, a basic amino acid residue, an alkanolamine residue having a C 2-3  hydroxyalklyl group, or aliphatic alkanolammonium. 
     
     
       2. The water/supercritical carbon dioxide microemulsion according to  claim 1 , wherein the amount of the water (molar ratio (W 0 )) is 0.001 to 1,000 mol with respect to 1 mol of the surfactant under a condition with a temperature of 75° C. and a pressure of 30 MPa. 
     
     
       3. The water/supercritical carbon dioxide microemulsion according to  claim 1 , wherein the perfluoroalkyl group has a carbon atom number of to 6. 
     
     
       4. The water/supercritical carbon dioxide microemulsion according to  claim 1 , wherein the perfluoroalkyl group has a carbon atom number of 4. 
     
     
       5. The water/supercritical carbon dioxide microemulsion according to  claim 1 , wherein M is an alkali metal.